Evaporative and illusionary snow systems have been described in U.S. Pat. Nos. 6,321,559; 6,474,090; 6,474,091; and 6,868, 691. These machines do not lend themselves to effectively producing evaporative and illusionary snow in a portable apparatus.
Specifically, previous machines required a flake generator incorporating and impeller and fan to project the flakes away from the apparatus.
The present invention utilizes Venturi effect to produce the flakes and protect them from the apparatus. DOS the present invention is simple or to manufacture and use because it does not require an impeller and incorporated fan with a flake generator in order to create evaporative snowflakes and propel them from the apparatus.
The Venturi effect is an example of Bernoulli's principle, in the case of incompressible fluid flow through a tube or pipe with a constriction in it. The fluid velocity must increase through the constriction to satisfy the equation of continuity, while its pressure must decrease due to conservation of energy: the gain in kinetic energy is supplied by a drop in pressure or a pressure gradient force.
The limiting case of the Venturi effect is choked flow, in which a constriction in a pipe or channel limits the total flow rate through the channel, because the pressure cannot drop below zero in the constriction. Choked flow is used to control the delivery rate of water and other fluids through spigots and other valves.
The portable apparatus of the present invention utilizes a source of compressed gas to produce in the desired pressure and airflow for the effective creation of evaporative snow.